Avaliação de metodologias de correção da reflectância do topo da atmosfera para Landsat 8 OLI

Abstract

This paper shows an evaluation of three top of atmosphere reflectance correction methodologies for the Landsat 8 OLI and the difference between the methodologies. The methodologies used in this paper are Geosud ToA 16 bits, Landsat Ecosystem Disturbance Adaptative Processing System (LEDAPS), and the mathematical formulas present in the Landsat 8 User Guide. These methodologies were applied in 15 different scenes, that were chosen in the globe, being distributed in Paraná, Brazil, Campo Mourão region, Coconino County Arizona, USA and in the Mongolian and Chinese landmark, Gashuun Sukhait’s Mongolian city region. After the generation of the correct scenes, was used the vegetation index Normalized Difference Vegetation Index – NDVI, to be able to compare these data, beyond NDVI’s application in the raw image for control purposes. Pearson’s correlation was used as a comparison tool. Was found that a strong correlation exists between the raw image with Geosud 16 NDVI’s; and LEDAPS with User Guide algorithm formulas NDVI, the correlations from 0.9 to 1 “very strong” in 100% and 94%, respectively. It is possible to say that Geosud’s correction does not follow the other two methodologies, because there are not correlated, as it correlated with the raw image, in other words, as if no correction had been made.